Exposure to air contaminated with small suspended particles (less than 2.5 microns, PM 2.5) for relatively short periods of time (hours or days) causes more than a million premature deaths each year, according to a new report carried out in more than 13,000 cities and towns around the world by a scientific team led by experts from Monash University (Australia), whose results have been published in the journal The Lancet Planetary Health (March 5).
To date, most studies have focused on the health impacts of living in cities where pollution levels are consistently high, ignoring the frequent pollution "spikes" that can affect smaller urban areas and occur, for example, landscape fires, dust, and other extreme intermittent air emissions. Pollution concentration events.
Led by Professor Yuming Guo, the study is important because it is the first to look at short-term exposure globally, rather than the long-term impacts of persistent exposure, as is the case for people living in cities. with high levels of contamination.
Researchers found that breathing PM 2.5 for even a few hours, and up to a few days, causes more than a million premature deaths worldwide each year, particularly in Asia and Africa, and more than a fifth (22 .74%) of occurred in urban areas.
According to Professor Yuming Guo, the short-term health effects of exposure to air pollution are well documented, “such as the megafires in Australia during the so-called Black Summer of 2019-20, which caused an estimated 429 deaths.” related premature deaths and 3,230 hospital admissions as a result of acute and persistent exposure to extremely high levels of wildfire-related air pollution,” indicates the study's lead author.
In this sense, the author highlights that he now presents more general data that represents "the first study that maps the global impacts of these brief periods of exposure to air pollution."
Those responsible for this publication add that due to the high population density in urban areas along with high levels of air pollution it is complex but crucial, “understanding the mortality burden associated with short-term exposure to PM 2.5 in these areas, because it is necessary to mitigate the negative effects of air pollution on the population of urban areas.
According to the study, Asia accounted for approximately 65.2% of global mortality due to short-term exposure to PM 2.5: Africa 17.0%, Europe 12.1%, America 5.6% and Oceania 0. 1%.
The mortality burden was highest in populated and highly polluted areas in East Asia, South Asia and West Africa, and the fraction of deaths attributable to short-term exposure to PM 2.5 in East Asia was more than 50% higher than the world average.
Most areas of Australia experienced a small decline in the number of attributable deaths, but the fraction of attributable deaths increased from 0.54% in 2000 to 0.76% in 2019, which was higher than any other subregion. One possible reason could be the increasing frequency and scale of extreme weather-related air pollution events, such as the 2019 wildfires.
The study recommends that, where health is most affected by acute air pollution, the implementation of specific interventions (such as air pollution alert systems and community evacuation plans) to avoid transient exposure to high concentrations of PM 2, 5 could mitigate its serious health damage.
